I spent 23 years working for an electric utility. I knew a lineman who was killed by “just 220”. It’s not the voltage. It only takes 0.10 amps to stop your heart.
Hooking the mast to a separate ground is a mistake. If you’re planning to ground the mast, which isn’t a bad idea, you are required to connect that ground to your service ground, which should be right there where your service entrance is anyway. I’ll come back and post a link to a short and easy to understand article, here: https://reeve.com/Documents/Articles Papers/Reeve_AntennaSystemGroundingRequirements.pdf
For your antenna feedline, you should ideally bring it into a lightning arrester first before bringing it into your house, but disconnecting it outside whenever it’s not in use will offer protection. Disconnecting it inside the house protects your radio but still gives lightning a path into your house.